The present invention relates to stuffing boxes in general, and more particularly to improvements in glands which serve to compress one or more stuffing box packings in the receptacles of stuffing boxes for rotary and/or reciprocable members, for example, for the shafts of pumps or for the spindles of valves.
The gland of a stuffing box is normally designed to engage the internal surface of the receptacle for the packing or packings and to remain spaced apart from the periphery of the movable member (hereinafter called shaft). Means is provided to move the gland axially so as to effect a compression of the packing or packings in the receptacle whereby the compressed packing or packings bear against the periphery of the shaft and prevent or reduce leakage of a fluid along the shaft. As a rule, the gland of a stuffing box consists of cast iron. Such glands can be mass-produced at a relatively low cost; however, they normally require at least some expensive and time-consuming secondary treatment, normally a mechanical treatment which is needed to insure an accurate fit in the receptacle and the absence of contact with the periphery of the shaft. Another drawback of cast iron glands is that their resistance to corrosion is low, i.e., they are likely to be attacked by the corrosive ingredients of air at the outer side of the stuffing box and by a gaseous or liquid fluid which is to be confined by the packing or packings of the stuffing box. It was already proposed to employ high-quality metallic materials, especially steel; however, this contributes significantly to the initial cost of the stuffing box.